Vehicles such as motorcoaches and the like are also put in action quite frequently in cold conditions, such as e.g. in winter for conveying passengers to winter-sports areas and the like. In order to meet the requirements with regard to comfort it is necessary thereby that on the one hand an even temperature is maintained in the passenger room, whilst on the other hand it must be possible to exhaust stale air and supply fresh air continuously.
With known vehicles it appears impossible to do so and there is occurrence of draught near doors and emergency hatches, whilst further there is a bad distribution of heat in the vehicle and therefore large differences in temperature occur in the vehicle. In particular with the known coaches the temperature adjustment in the coach is thereby strongly influenced by the heating device located near the driver, which is adjusted by the driver dependent on his requirements, e.g. in connection with preventing the occurrence of mist on the windows and the like.
The invention now aims at effecting a method by means of which an even and pleasant temperature can be achieved in the coach while maintaining a regular air-change.
According to the invention this can be achieved because near both longitudinal sides of the vehicle, near the floor, air is supplied via an air heating device to the passenger room of the vehicle kept under excess pressure, whereby part of said air supplied via the air heating device is sucked from the inside of the vehicle and part of the air from the outside, whilst further outside air is supplied near the roof, all this in such a manner that the total quantity of outside air supplied per time unit is kept at least substantially constant, whilst the quantity of outside air led through the air heating device is regulated dependent on the quantity of heat to be supplied which is required.
When using the method according to the invention it will be possible to maintain the desired temperature in the passenger room while still sufficient outside air is constantly supplied, whereby the cold outside air supplied near the roof will soon mix with the rising hot air, so that supplying cold air at this spot does not result in discomfort for the passengers, while undesired occurrence of draught is also opposed by keeping the inside of the passenger room under excess pressure.
All this can be achieve in a simple manner in a vehicle provided with a passenger room bounded by a floor, a roof and upright walls as well as with an air heating device and fans by means of which air can be blown, via the air heating device, into air supply ducts extending along the floor, whereby according to the invention the vehicle is provided with a pair of air heating devices and air can be supplied via each air heating device by means of a pair of fans to an air supply duct extending along a side of the vehicle whereby by means of one of the fans air sucked from the passenger room is displaced and air sucked from the outside is displaced by the other fan, whilst near each side of the vehicle a further fan has been provided via which outside air can be supplied to an air supply duct located near the roof and extending into the longitudinal direction of the vehicle, and means have been provided which regulate the speed of revolutions of the fans supplying outside air dependent on the demand for heat in such a manner that with a decreasing demand for heated air to be supplied the speed of revolutions of the fan supplying outside air via the heating device decreases and the speed of revolutions of the other fan supplying outside air increases and with an increasing demand for heat the speed of revolutions of the fan supplying outside air via the heating device increases and the speed of revolutions of the other fan supplying outside air decreases all this in such a manner that the quantity of outside air supplied per time unit stays at least substantially constant.